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| author | Laszlo Ersek <lersek@redhat.com> | 2016-01-19 10:46:34 +0000 |
|---|---|---|
| committer | lersek <lersek@Edk2> | 2016-01-19 10:46:34 +0000 |
| commit | dfc229f6a67b03e3c47b67b92982a100cfef738a (patch) | |
| tree | 90555ba0e9e0e6fea8a1a15e7462d97e9be0c29b /MdeModulePkg | |
| parent | 3b672240e6c77ccf3f5cc0f3e8dbf026fc9e2751 (diff) | |
| download | edk2-platforms-dfc229f6a67b03e3c47b67b92982a100cfef738a.tar.xz | |
MdeModulePkg/.../IdeMode: actualize DRQReady*() comment blocks
The DRQReady() and DRQReady2() functions only differ in that they poll
different status registers for BSY, ERR, and DRQ: the former looks at the
Status Register (clearing interrupt status), while the latter looks at the
Alternate Status Register (not clearing interrupt status).
They both correctly return a unique status code, EFI_NOT_READY, for the
BSY==0 && ERR==0 && DRQ==0
case; that is, when the device reports "command complete".
However, the functions' leading comments don't explain this case, so it's
easy to miss in callers. Update the comments.
Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: John Snow <jsnow@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19684 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'MdeModulePkg')
| -rw-r--r-- | MdeModulePkg/Bus/Ata/AtaAtapiPassThru/IdeMode.c | 31 |
1 files changed, 25 insertions, 6 deletions
diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/IdeMode.c b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/IdeMode.c index f74e5ca373..b06f9889ed 100644 --- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/IdeMode.c +++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/IdeMode.c @@ -467,9 +467,18 @@ DRQClear2 ( @param IdeRegisters A pointer to EFI_IDE_REGISTERS data structure.
@param Timeout The time to complete the command, uses 100ns as a unit.
- @retval EFI_SUCCESS DRQ bit set within the time out.
- @retval EFI_TIMEOUT DRQ bit not set within the time out.
- @retval EFI_ABORTED DRQ bit not set caused by the command abort.
+ @retval EFI_SUCCESS BSY bit cleared and DRQ bit set within the
+ timeout.
+
+ @retval EFI_TIMEOUT BSY bit not cleared within the timeout.
+
+ @retval EFI_ABORTED Polling abandoned due to command abort.
+
+ @retval EFI_DEVICE_ERROR Polling abandoned due to a non-abort error.
+
+ @retval EFI_NOT_READY BSY bit cleared within timeout, and device
+ reported "command complete" by clearing DRQ
+ bit.
@note Read Status Register will clear interrupt status.
@@ -542,9 +551,19 @@ DRQReady ( @param IdeRegisters A pointer to EFI_IDE_REGISTERS data structure.
@param Timeout The time to complete the command, uses 100ns as a unit.
- @retval EFI_SUCCESS DRQ bit set within the time out.
- @retval EFI_TIMEOUT DRQ bit not set within the time out.
- @retval EFI_ABORTED DRQ bit not set caused by the command abort.
+ @retval EFI_SUCCESS BSY bit cleared and DRQ bit set within the
+ timeout.
+
+ @retval EFI_TIMEOUT BSY bit not cleared within the timeout.
+
+ @retval EFI_ABORTED Polling abandoned due to command abort.
+
+ @retval EFI_DEVICE_ERROR Polling abandoned due to a non-abort error.
+
+ @retval EFI_NOT_READY BSY bit cleared within timeout, and device
+ reported "command complete" by clearing DRQ
+ bit.
+
@note Read Alternate Status Register will not clear interrupt status.
**/
|